We are so used to seeing certain everyday things that we just don’t pay attention to details. But very often the most ingenious ideas or fascinating stories are hidden behind some unremarkable features.
With that in mind, we at have gathered together the 9 most stunning secrets of familiar things that no one noticed.
A mysterious tram’s zigzag
If you look closely at a tram’s overhead lines, you’ll see that its contact wires zigzag back and forth instead of going in a straight line.
The thing is that all trams have pantographs attached to their roofs. The upper part of the pantograph is gradually worn down by the overhead wire and eventually needs to be replaced. To wear it down evenly, the wire is not installed strictly along the tram’s path but in zigzag patterns. As the tram moves, the pantograph slides along the wire and it wears down evenly.